Lubricating oil and process for preparing same



Patented Mar. 27, 1934 UNITED STATES LUBRICATING OIL AND PROCESS FOR PRE- PARING SAME Leonard S. Bonnell, Roselle, N. J., assignor to Standard-I. G.

Company No Drawing. Application June 23, 1930,

Serial No. 463,355

7 Claims.

This invention relates to improved lubricating oils and a process for preparing them. More specifically it relates to blends of heavy hydrocarbon oil with petroleum residues or heavy cuts thereof, such as cracking coil tar and the like, which have been treated by a process of hydrogenation.

It is well known that materials such as cracking coil tar, or heavy cuts thereof, have the effect of reducing the pour point of the lubricating oil to which they may be added, but the addition of such material in efiective quantity to a high grade lubricating oil results in an objectionable black color and other undesirable characteristics.

I have found that by subjecting the said petro leum residues to a process bf hydrogenation un der high pressure and subsequently separating from the hydrogenated product any lighter fractions which may be formed in the hydrogenation operation, the products obtained from this treatment may be blended with heavy hydrocarbon oils to produce improved lubricating oils. Their ability to reduce the pour point is unimpaired, while their damaging. effect on the color and quality of the oil to which they are added has been practically eliminated. In fact, I have observed that the addition. of a hydrogenated petro leum residue to a lubricating oil not only improves the quality of the oil, but at the same time produces in the oil a bloom characteristic of high grade Pennsylvania, lubricating oil.

The hydrogenation of the residue may be carried out in any suitable manner, but in general I prefer to operate at'temperatures above about 750 F. and under pressures above about 25 atmospheres and even at 200 atmospheres or higher. The material may be hydrogenated before its addition to the lubricating oil or it may be added to the lubricating oil first and the mixture hydrogenated. In the latter case the lubricating oil may be further improved by hydrogenation. It will be understood that at the high temperatures employed some breaking down of the oil into lighter fractions takes place andthese lighter fractions are separated from the heavier oil by any suitable method of separation, such as by distillation, for example.

The hydrogenation reaction may be facilitated by the use of hydrogenation catalysts such as a mixture of chromium and molybdenum oxides, or sulfides, or a mixture of molybdenum and tungsten oxides or sulfides, or mixtures of other metallic oxides with similar properties, and these materials may be either suspended in the oil or maintained in lump form in contact with the oil in a suitable reactor.

As an example of my process, 5% by volume of an extract obtained from West Texas cracking coil tar by extracting it with naphtha, and

then distilling ofi the naphtha, was added to a Colombian lubricating distillate of 617 seconds viscosity Saybolt at 100 F. It has been found that the naphtha-free extracts in general contain the more active pour inhibiting portions of the tar. This mixture was hydrogenated at 775 F. and 200 atmospheres pressure in contact with a mixture of molybdenum, zinc and magnesium oxides.

The hydrogenated product was cooled and .subsequently separated into lubricating oil fractions. One such fraction, an oil of 52 seconds viscosity Saybolt at 210 F. separated froin this'product showed (after clay filtration) the following inspection: v 76 Gravity A. P. I 25.9 Pour Below 15 F. Color 5 /2 Robinson Hydrogenation of the same Columbia lube distil- 80 late without addition of cracking coil tar gave a 52 seconds viscosity Saybolt oil of this inspection:

Gravity A. P. I 27.9 Pour Above 35 F. Color 7% Robinson It will be observed that the oil containing the cracking coil tar has, after hydrogenation, a pour point about 20 F. lower, and a color only two points Robinson lower than the similarly treated oil to which the cracking coil tar has not been added.

Improved lubricating oils can also be prepared by blending hydrogenated residue with an unhydrogenated oil. Hydrogenation of an oil, however, generally raises the pour point and the hydrogenated residue is therefore peculiarly adapted for blending with such oils because of its similar treatment and appearance. Further, waxy constituents are sometimes added to low cold test oils to improve their viscosity index and I have found that the hydrogenated residue may be used to lower the pour points of these blends also.

The quantity of hydrogenated pour inhibitor that must be added varies with the type of oil, but in general will be from 2 to 15%. Hydrogenated oils having pour points of 20 F., 30 F. and even 60 F. may be blended with this agent to produce oils with a pour point below 10 F. or

below 0 F.

Hydrogenation stabilizes the cracked residue and its blends therefore will not darken or deteriorate on standing.

This invention is not to be limited to any specific example given for illustrative purposes, but will be understood to include any such applications as properly come within its scope.

I claim:

,1. Improved lubricating oil having a pour point below about 10 F. comprising a major proportion of a hydrocarbon oil having a pour point of about 60 F. with a minor proportion of a hydrogenated tar produced in the cracking of petroleum.

2. Improved lubricating oil having a pour point of about zero degrees F. comprising a blend of a heavy hydrocarbon oil having a pour point of about 30 F. with the heavier fraction of a hydrogenated residue of a petroleum cracking process.

3. Method of reducing the pour point of a heavy wax containing hydrocarbon oil which comprises adding thereto a few per cent of a hydrogenated residue of a petroleum cracking process.

, 4. Method according to claim 3 in which about 5% of the hydrogenated residue is added to the oil. I I

5. Method according to claim 3 in which about 10% of the hydrogenated residue is added to the oil.

6. Process for reducing the pour point of a heavy wax containing hydrocarbon oil which comprises adding thereto a few per cent of a residue of a petroleum cracking process and then subjecting the mixture to destructive hydrogenation.

'7. Method of reducing the pour point of lubricating oil having a high pour point which comprises adding thereto a few per cent of a hydrogenated residue of a petroleum cracking r-ocess.

LEONARD S. BONNELL. 

